New technology captures carbon dioxide, compresses it and sequesters it underground.

How can we reduce the emissions from the more than 600 coal-fired electric plants in the United States? One method is to try to capture the carbon dioxide emitted by the plants before it enters the atmosphere and then sequester it underground. A new technology designed to do just that went into operation in June 2011 and captured its 100,000th ton of CO2 this fall, according to a report from Power Engineering magazine.

The technology is being used at Alabama Power's James M. Barry Electric Generating Plant near the city of Mobile. Alabama Power is a subsidiary of Southern Company, which partnered with Mitsubishi Heavy Industries (MHI) to implement the carbon-capture technology. (Southern Company is a sponsor of Mother Nature Network.)

The project got its start back in 2009 when the U.S. Department of Energy (DOE) invested $979 million in three carbon capture projects, including Plant Barry and other projects in West Virginia and Texas. The total cost for all three projects was projected at the time to be $3 billion, two-thirds of which would come from the power industry. Some of the DOE's funds were provided by the American Recovery and Reinvestment Act.

When it was announced, the DOE provided this description of the Plant Barry operation: "Southern Company Services will retrofit a CO2 capture plant on a 160-MW flue gas stream at an existing coal-fired power plant... The captured carbon will be compressed and transported through a pipeline, and up to one million metric tons per year of carbon will be sequestered in deep saline formations. Southern Company Services will also explore and use potential opportunities for beneficial use of the carbon for enhanced oil recovery."

After more than a year of testing, the plant began sequestering carbon underground on August 20 of this year. A press release at the time from MHI called this "an important milestone in the world's first integrated carbon capture and sequestration project for flue gas from a coal-fired power plant — which contains significant quantities of impurity — on a scale of 500 metric tons per day."

The CO2 captured from the plant is captured, compressed, and then sequestered "in a saline formation at a depth of 3,000-3,400 meters in the Citronelle Dome geologic structure, which is approximately 12 miles west from the plant."

"Energy innovation projects like this are critical to providing meaningful solutions for our energy future," Chris Hobson, Southern Company chief environmental officer told Power Engineering magazine in November. "The work we are doing with our partners at Plant Barry to reduce greenhouse gas emissions reflects our commitment to lead the industry with a robust research and development portfolio."

Although it is still billed as a "demonstration project," the technology employed at Plant Barry could be implemented in other locations once the test period for the technology is completed, according to MHI and Southern Company.